1. Field of the Invention
The present invention relates to a power conversion device, and more particularly to the main circuit switching components thereof being constructed so that the reflux diode is in anti-parallel connected.
2. Description of the Related Art
Conventionally, inverter devices, as shown in FIG. 1 are constructed so that reflux diode Du.about.Dw and Dx.about.Dz are connected anti-parallel to MOSFET Su.about.Sw and Sx.about.Sz. In the case of this construction, when MOSFET Su.about.Sw and Sx.about.Sz are turned off, the electrical current energy stored in load M circulates via reflux diode Du.about.Dw and Dx.about.Dz.
However, in the above mentioned conventional construction, if MOSFET Su is turned ON when forward flowing current Ia is flowing through reflux diode Dx, the voltage between PN (namely direct current link voltage) is added as inverse bias to both ends of reflux diode Dx, and as shown in FIG. 2, reflux diode Dx disconnects after the reverse current has flowed due to the residual charge in reflux diode Dx. Because of this, a large loss occurs in reflux diode Dx due to the voltage between PN and the reverse current, necessitating the enlargement of the radiator.